Field of the Invention
The present disclosure relates generally to a method and apparatus for cutting one or more openings in a sidewall of a spiral pipe. More particularly, the present disclosure relates to a method and apparatus for cutting one or more openings in a sidewall of the spiral pipe, such as register holes or taps, wherein the one or more register holes and/or taps are cut as the spiral pipe is formed.
Description of the Related Art
Spiral pipes, such as pipes used for ductwork in the heating and air conditioning industry, are well known. In general, the spiral pipe is formed from a single continuous strip of sheet metal which is rolled and joined at the seam of overlapping sections. The strip of sheet metal first passes through one or more flange forming rollers that bend the side edges of the strip. The strip is then fed at an angle and engages a drum-like forming head that curls the strip in a helical manner. The side edges of adjacent sections of the strip are joined and compressed to form a locking seam. By varying the width of the sheet metal strip, the angle at which the sheet metal strip is fed into a pipe forming machine, and the shape and size of the forming head, the diameter, length, and the shape of the spiral pipe can be controlled. Various pipe forming machines exist in the art to form spiral pipes of various diameters and lengths.
Conventional pipe forming machines are configured only to form a length of pipe. Additional secondary operations, such as cutting of the openings to receive heating and air conditioning registers and taps, are performed independently of the pipe forming machine. For example, in order to cut a register hole or a tap on a preformed spiral pipe, a template of the opening is first outlined on the exterior sidewall of the pipe and the opening is then cut out using sheet metal shears or a powered sheet metal cutting tool. This process is labor intensive. In a large building, dozens of register holes and/or taps must be cut in the spiral pipe ductwork. Because the cutting process is performed manually, significant time and cost must be dedicated to this operation. Even in instances where register and/or tap hole cutting is performed by a machine, a spiral pipe is first be formed, after which the spiral pipe is loaded to a separate machine for cutting the register holes and/or taps.